make MergeableCString be a SectionKind "abstract class", and
add new concrete versions for 1/2/4-byte mergable strings.

These are not actually created yet.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78055 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/AsmPrinter/PPCAsmPrinter.cpp b/lib/Target/PowerPC/AsmPrinter/PPCAsmPrinter.cpp
index 5794a17..12a6da7 100644
--- a/lib/Target/PowerPC/AsmPrinter/PPCAsmPrinter.cpp
+++ b/lib/Target/PowerPC/AsmPrinter/PPCAsmPrinter.cpp
@@ -905,6 +905,7 @@
     getObjFileLowering().SectionForGlobal(GVar, Mang, TM);
   SwitchToSection(TheSection);
 
+  /// FIXME: Drive this off the section!
   if (C->isNullValue() && /* FIXME: Verify correct */
       !GVar->hasSection() &&
       (GVar->hasLocalLinkage() || GVar->hasExternalLinkage() ||